Transcript Week 2 Lecture - Environmental Studies Program

Announcements
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Assignment for discussion section
• read Bradshaw and Bekoff paper
• come to section prepared to discuss questions
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Change in Kevin’s office hours
Check out the website:
www.es.ucsb.edu/classes/envs100/
Summary
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What is Ecology?
Ecology vs. Environmentalism
Observation and Experimentation
The Scientific Method
Roots of Ecology
Theory of Evolution by Natural Selection
Two-minute quiz:
Ecology is (pick the best answer):
1. the study of the distribution of plant and
animal species across the earth
2. the same as environmental science
3. the study of how abiotic factors determine
the evolution of animals and plants
4. a method for classifying organisms
5. a relatively old science
6. the study of the relationships of living things
to one another and their environment
Theory of Evolution by Natural Selection
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lineages with the most appropriate biological
programming (genes) for the current conditions
will leave the most descendants
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what is a lineage?
• family group
• coming from a common ancestor
Defining ‘evolution’
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Scientific definition vs. common usage
Defining ‘evolution’
Scientific Definitions:
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All the changes that have transformed life on earth
from its earliest beginnings to the diversity that
characterizes it today
–Neil Campbell
Defining ‘evolution’
Scientific Definitions:
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All the changes that have transformed life on earth
from its earliest beginnings to the diversity that
characterizes it today
–Neil Campbell
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The origination of species of animals and plants…
–O.E.D.
Defining ‘evolution’
Scientific Definitions:
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All the changes that have transformed life on earth
from its earliest beginnings to the diversity that
characterizes it today
–Neil Campbell
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The origination of species of animals and plants…
–O.E.D.
From a scientific point of view, evolution is just
how new species come about
…and evolution does not mean “getting better”
Defining ‘evolution’
Scientific Definitions:
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All the changes that have transformed life on earth
from its earliest beginnings to the diversity that
characterizes it today
–Neil Campbell
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The origination of species of animals and plants…
O.E.D.
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Common Usage:
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A process of continuous change from a lower,
simpler, or worse to a higher, more complex, or
better state
–Merriam-Webster’s Dictionary
Humans and evolution
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Where does the “getting better” idea
come from?
• view of humans as an evolutionary endpoint
Humans and evolution
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Where does the “getting better” idea
come from?
• view of humans as an evolutionary endpoint
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Humans and natural selection
• humans are different
• the “unfit” often live to reproduce
• strong culture
• direct contact with nature is limited
• ubiquitous presence
Where does ecology fit in?
Biological Sciences
Physical Sciences
Earth Sciences
Where does ecology fit in?
Biological Sciences
Ecology
Physical Sciences
Earth Sciences
• Ecology is an interdisciplinary science
• Ecological studies are done at the interface of these 3 fields
Organization within Ecology
Ecosystem Ecology
Community Ecology
Population Ecology
Behavioral Ecology
Physiological Ecology
Ecology subfields:
• Physiological Ecology:
• the study of the diverse adaptations that enable
organisms to function in their environment
Ecology subfields:
• Behavioral Ecology:
• the study of the
ecological and
evolutionary basis for
animal behavior
• the roles of behavior in
enabling animals to
adapt to their
ecological niches

Mimic Octopus Video
Clip
Ecology subfields:
• Behavioral Ecology:
• the study of the
ecological and
evolutionary basis for
animal behavior
• the roles of behavior in
enabling animals to
adapt to their
ecological niches
• does “plant behavior”
exist?
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Mimic Octopus Video
Clip
Plant behavior
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behavior is defined as “an observable response
to environmental stimuli” –Starr and Taggart
Plant behavior
behavior is defined as “an observable response
to environmental stimuli” –Starr and Taggart
• nervous and endocrine systems are often at
work in animals
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Plant behavior
behavior is defined as “an observable response
to environmental stimuli” –Starr and Taggart
• nervous and endocrine systems are often at
work in animals
• plants have hormones and signaling pathways
but no “brain”
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Plant behavior
behavior is defined as “an observable response
to environmental stimuli” –Starr and Taggart
• nervous and endocrine systems are often at
work in animals
• plants have hormones and signaling pathways
but no “brain”
• plants respond to stimuli such as light, gravity,
and touch
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Plant behavior
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behavior is defined as “an observable response
to environmental stimuli” –Starr and Taggart
nervous and endocrine systems are often at
work in animals
plants have hormones and signaling pathways
but no “brain”
plants respond to stimuli such as light, gravity,
and touch
sometimes the responses are very slow
Plant behavior
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behavior is defined as “an observable response
to environmental stimuli” –Starr and Taggart
nervous and endocrine systems are often at
work in animals
plants have hormones and signaling pathways
but no “brain”
plants respond to stimuli such as light, gravity,
and touch
sometimes the responses are very slow
plants in motion
Plant behavior
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behavior is defined as “an observable response
to environmental stimuli” –Starr and Taggart
nervous and endocrine systems are often at
work in animals
plants have hormones and signaling pathways
but no “brain”
plants respond to stimuli such as light, gravity,
and touch
sometimes the responses are very slow
plants in motion
very few people study the “why’s”
Ecology subfields:
• Population Ecology:
• the study of individuals of a certain species
occupying a defined area during a specific time
Ecology subfields:
• Community Ecology:
• the study of how populations of organisms interact
Ecology subfields:
• Ecosystem Ecology:
• the study of interactions between organisms and
their environment as an integrated system
Different types of ecologists ask
different types of questions.
Scale
Question
Global
ecosystem
How does carbon loss from
plowed soils influence global
climate?
Watershed
How does deforestation
influence the water supply to
nearby towns?
Forest
ecosystem
How does acid rain influence
forest productivity?
Endolithic
ecosystem
What are the biological
controls over rock
weathering?
Temporal Scale
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Length of time
Type of process is important:
• many ecological processes take decades
• unfortunately funding usually lasts for only 3 years
• LTER
• biology can be nearly instantaneous
• geological processes are very slow
• chemistry can be fast or slow
• enzymatic activity
• lifetime of certain gases in the atmosphere
Spatial Scale
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“Powers of Ten” Online Demo
Summary for today…
Definition of ‘lineage’ and ‘evolution’
• Humans and evolution
• Ecology as an interdisciplinary science
• Different subfields in Ecology:
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Physiological Ecology
Behavioral Ecology
Population Ecology
Community Ecology
Ecosystem Ecology
Temporal and Spatial scale in ecology
Announcements
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Handouts
• I have more copies
• You can also get them online:
www.es.ucsb.edu/classes/envs100/
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My office hours: Mondays 10:15-12:00pm
Panel on careers in the environment?
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Fish and Wildlife/Fish and Game
Non-governmental organizations
Consulting firms and private companies
Education
From Monday…
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Scientific vs. common use of the word
“evolution”
Subfields of Ecology
Scale
Two-minute quiz…
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Imagine that you are an ecosystem
ecologist. You travel to rural Costa Rica,
where several of the people you meet
work on banana plantations.
You visit a plantation, and then decide to
incorporate a study of one into your
research program. Which one of the
following questions might you pursue as
part of your research?
1.
2.
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How does the fruit-eating bat population
respond after a banana plantation is
abandoned?
How many different species of ant live in a
banana plantation, and how does this number
compare with an equally-sized patch of
rainforest?
How much nitrogen enters streams from a
banana plantation in comparison to old growth
rainforest?
How complex are the insect-based food webs
in a pesticide-free banana plantation?
Which contains foliage that is more difficult to
consume, a banana plant or a walking palm?
What is an ecosystem?
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All the organisms and the abiotic entities
with which they interact within a given
space
The space is delineated by the person
studying it
• Can be as large as the whole earth
• Can be as small as a test tube
• What determines the appropriate scale?
What is an ecosystem process?
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Transfer of materials or energy from one
pool to another
• Can involve biotic and abiotic components of
the system
What regulates the function of
ecosystems?
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Feedback mechanisms
Energy flow
Feedback mechanisms
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Positive feedback
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B
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Negative feedback
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B
Positive feedback
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Can push system to a new state
Ice reflects the sun’s rays
warming
With less ice, the darker
surface of land and ocean
absorb more heat
Positive feedback
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Can push system to a new state
Fertile soil
Rich litter
Fast decomposition
Rapid nutrient
release
Negative feedback
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Tends to keep a system stable
Prey
Predator
Energy Flow
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Climate:
transport of energy through the earth system
• key control over distribution of earth’s
ecosystems
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Biology:
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controls the transfer of energy within and
between organisms
Where does energy come from?
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The sun
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Geothermal activity
What happens to energy from the sun?
Reflected by clouds and
atmosphere
23
albedo
100
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Absorbed by
atmosphere and 20
clouds
Reflected by surface
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2
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Absorbed in photosynthesis
Absorbed as heat
Energy Budget
• Albedo: depends on reflectivity
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Water: 2%
Snow: 50-90%
Clouds: 90%
Vegetation: 5-30%
• Photosynthesis: 2%  chemical energy
• Heat: the rest (8-90%)  drives climate
Weather vs. Climate
Weather describes
short term variability
• Difficult to predict
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The Butterfly Effect
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Link to “butterfly
effect” online demo
"sensitive dependence upon initial conditions"
Weather, chaos, and the butterfly effect
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Meteorologist Edward Lorenz, a pioneer of chaos
theory, coined the famous phrase “the butterfly
effect”.
The work of weather, he argued, can ultimately
magnify the flapping of a butterfly’s wings into a
typhoon.
The phrase has become shorthand for the way tiny
factors working through complex systems can work
huge changes in history.
'Chaotic' motion is not completely random. Although
precise details of the motion cannot be predicted,
patterns can be seen in the chaos.
Weather vs. Climate
• Weather describes
short term variability
• Difficult to predict
• Climate describes
typical conditions for
a region
• More predictable
• Heat moves air
• Depends on M.O.L.E.:
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mountains
oceans and lakes
latitude
elevation
Uneven Heating of Earth
Greater heating at
equator than poles
• sun’s rays hit more
directly
• less atmosphere to
penetrate
Therefore
• net gain of energy at
equator
• net loss of energy at
poles
Heat Moves Air
Air rises at equator and
subsides at poles
(vertical circulation)
Atmosphere contains
circulation cells at
different latitudes
Earth’s rotation
determines
• wind direction
• horizontal circulation
(Coriolis force)
Mountains: orographic lift
Ocean: surface currents
Ocean: deep conveyor
Ocean
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surface currents are driven by wind
Ocean
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surface currents are driven by wind
Coriolis forces deflect current away from
western edges of continents
Ocean
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surface currents are driven by wind
Coriolis forces deflect current away from
western edges of continents
Formation of gyres
Ocean
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surface currents are driven by wind
Coriolis forces deflect current away from
western edges of continents
Formation of gyres
40% of latitudinal heat transfer from
equator to poles occurs through the ocean
• surface (warm) currents move towards poles
• deep (cold) currents move towards equator
The Lake Effect
If the lake is warm but
the air blowing across it
is cold:
If the lake is cold but
the air blowing across it
is warm:
Water vapor rises from
the warm lake, and
condenses and forms
rain in cold air.
Warm, moist air is
cooled as it passes over
the cold lake, and fog
forms.
Latitude: seasons and the earth’s tilt
Elevation
• Adiabatic cooling
• Katabatic wind
• pooling of cold air in
valleys
10° C
Air cools as
pressure
decreases
25° C
Also: more rain at higher elevations due to orographic lift!
Vegetation
• Climate determines what plants can survive
• Vegetation, in turn influences climate
• Surface Energy Budget
• darker vegetation has lower albedo
• decrease from grassland  deciduous forest
• uneven canopies create turbulence in airflow
• Water
• high evapotranspiration can lead to high
precipitation
Energy Flow
• Climate:
• transport of energy through the earth system
• Biology:
• controls the transfer of energy within and
between organisms
Announcements
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Handouts
• Wagener et al. article
• Questions: written assignment due in your
section next week (Oct. 7th or 8th)
• Writing guidelines will help you with the
assignment
• You can get all of these online:
www.es.ucsb.edu/classes/envs100/
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Women In Science & Engineering (WISE)
• [email protected]
Summary from Wednesday…
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Feedback mechanisms
• Positive
• Negative
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Energy Flow
Weather vs. Climate
The butterfly effect and chaotic systems
Uneven heating of earth drives climate
M.O.L.E.
Climate and Vegetation
Two-minute Quiz
(by the way…these “quizzes” are just to test your knowledge)
Which one of the following is true?
a. Chaos and randomness are the same thing.
b. The Coriolis Force is stronger in the Northern
Hemisphere than it is in the Southern
Hemisphere.
c. A small lake in northern Minnesota will have a
higher albedo in the winter than it does in the
summer.
d. The deep ocean conveyor moves water more
quickly than surface currents can.
e. The climate in a certain region is primarily
caused by biotic (rather than abiotic) factors.
Coriolis Force
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Earth spins more quickly at equator than near poles
Air moving from pole to equator begins to move more
slowly relative to the surface of the earth as it nears
the equator
Anything moving in a straight line along the northsouth axis will eventually curve
This causes deflection of air:
• to the right in the Northern Hemisphere
• to the left in the Southern Hemisphere
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Ocean water circulates:
• clockwise in Northern Hemisphere
• counterclockwise in the Southern Hemisphere
But what about hurricanes?
• Coriolis is only one of the forces acting on
air to cause winds
• Air-pressure differences draw air toward
the center of the area of low pressure
• This pressure-gradient force is stronger
than the Coriolis force
• The combination of the two forces leads to
a counter-clockwise spin of hurricanes
Coriolis Force along the coast
• Coriolis forces combined with prevailing
winds pull surface water:
• to the right in the Northern Hemisphere
• to the left in the Southern Hemisphere
• Therefore, surface current flows away
from western edges of continents
• Cold water rises from below to replace it
Energy Flow
• Climate:
• transport of energy through the earth system
• Biology:
• controls the transfer of energy within and
between organisms
Plant allocation
Where does the
energy go?
• roots
• stems
• leaves
• flowers
• fruits
• seeds
Animal allocation
• Growth
• Respiration
• Heat production
• endotherms
• ectotherms
• Behavior
• hunting or gathering
• reproduction
• other activities
Energy flow through endotherms
Energy flow through ectotherms
What limits how
much energy is
available in a kelp
forest food web?
What controls primary productivity?
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Light
Temperature
What controls primary productivity?
• Light
• Temperature
• Nutrients
• Nitrogen  proteins, nucleic acids
• Phosphorus  nucleic acids, ATP
• Others
• Potassium, Calcium, Magnesium, Iron, Molybdenum
What controls primary productivity?
• Light
• Temperature
• Nutrients
• Nitrogen  proteins, nucleic acids
• Phosphorus  nucleic acids, ATP
• Others
• Potassium, Calcium, Magnesium, Iron, Molybdenum